Mars exploration: Opportunity and Curiosity rovers

Encyclopædia Britannica, Inc.

Learn about the difference between prokaryotes and eukaryotes.

Contunico © ZDF Studios GmbH, Mainz

Overview of mint, including its cultivation, culinary and medicinal uses, history and mythology, and appearance under the microscope.

Encyclopædia Britannica, Inc.

Knowing the difference isn't just a technical distinction—it can save lives.

NASA

The Gemini program was conducted between 1964 and 1967 to give NASA engineers and astronauts information about spacecraft maneuvering, rendezvous, and ground control and about human performance in microgravity, in preparation for the Apollo voyages to the Moon. This video shows a Gemini spacecraft launch and booster separation. A Titan II rocket, a modified version of a rocket designed to carry nuclear warheads, lifts the spacecraft off the ground. Once the craft has cleared the Earth's atmosphere, the rocket is jettisoned, and it falls back to Earth. The Gemini craft was an enlarged version of the Mercury capsule and measured 5.8 metres (19 feet) long and 3 metres (10 feet) in diameter.

NASA/Dryden Research Aircraft Movie Collection

An X-15 rocket-powered research aircraft launching from a U.S. Air Force B-52, c. 1960s.

NASA

This animation shows the paths of the Voyager 1 and 2 spacecraft, which were designed to explore the outer planets of the solar system. The twin probes, each carrying 10 instruments, provided a wealth of new information about interplanetary space and the four giant gas planets and their moons. The Voyagers were launched in late 1977. In 1979 they reached Jupiter. Passing through the planet's gravitational field, they gathered enough energy to “slingshot” around the planet and head for Saturn. Voyager 1 reached Saturn in November 1980 and then headed out of the solar system. Voyager 2 continued on to Uranus, reaching the planet in January 1986. Changing course again and heading for Neptune, the spacecraft arrived at the outermost gas giant in August 1989. It then continued out of the solar system. In the first years of the 21st century, each craft was still sending back information about the outer reaches of the solar system and had traveled well beyond the orbit of Pluto.

SpaceX (A Britannica Publishing Partner)

Video released by the spacecraft maker SpaceX in August 2012 after it won a contract with NASA to prepare its Dragon spacecraft to carry astronauts into space.